In a saddle type vehicle such as a motorcycle, a canister for collecting evaporated fuel in a fuel tank is provided, and the fuel collected by the canister is used for combustion in an engine.
The canister includes a fuel collection section for absorbing evaporated fuel by means of activated carbon or the like. To the fuel collection section, a charge passage for introducing evaporated fuel in the fuel tank into the canister, a purge passage for purging the fuel absorbed by the fuel collection section with external air and supplying the purged fuel to an intake system of the engine as well as an atmosphere-opening passage for allowing the fuel collection section to communicate with the atmosphere are connected.
Since the atmosphere-opening passage is open at an end portion thereof to the outside, there is the possibility that dust on the road surface or in the atmosphere or water drops of rainwater or the like may penetrate the inside of the atmosphere-opening passage from the opening end of the same. Therefore, an atmosphere-opening structure for a canister for avoiding this has been proposed (refer to, for example, Japanese Utility Model Publication No. Hei 3-29573).
In the atmosphere-opening structure for a canister disclosed in Japanese Utility Model Publication No. Hei 3-29573, the atmosphere-opening passage connected to the fuel collection section of the canister is branched into two branch passages, and one of the branch passages is disposed such that the opening end thereof is directed downwardly in the proximity of the road surface while the other branch passage is attached at the opening end thereof to a vehicle body frame on the upper side of a tank frame or the like. Further, a check valve for preventing absorption of dust or water drops from the road surface is provided for the one branch passage disposed in the proximity of the road surface.